English verb conjugation
MUST CONCERTINA

Regular verb: concertina - concertinaed - concertinaed

Affirmation

Simple form	V-ing form
I must concertina you must concertina she must concertina we must concertina you must concertina they must concertina	I must be concertinaing you must be concertinaing she must be concertinaing we must be concertinaing you must be concertinaing they must be concertinaing
Perfect	V-ing perfect
I must have concertinaed you must have concertinaed she must have concertinaed we must have concertinaed you must have concertinaed they must have concertinaed	I must have been concertinaing you must have been concertinaing she must have been concertinaing we must have been concertinaing you must have been concertinaing they must have been concertinaing

Negation

Simple form	V-ing form
I mustn't concertina you mustn't concertina she mustn't concertina we mustn't concertina you mustn't concertina they mustn't concertina	I mustn't be concertinaing you mustn't be concertinaing she mustn't be concertinaing we mustn't be concertinaing you mustn't be concertinaing they mustn't be concertinaing
Perfect	V-ing perfect
I mustn't have concertinaed you mustn't have concertinaed she mustn't have concertinaed we mustn't have concertinaed you mustn't have concertinaed they mustn't have concertinaed	I mustn't have been concertinaing you mustn't have been concertinaing she mustn't have been concertinaing we mustn't have been concertinaing you mustn't have been concertinaing they mustn't have been concertinaing

Interrogative form

Simple form	V-ing form
must I concertina? must you concertina? must she concertina? must we concertina? must you concertina? must they concertina?	must I be concertinaing? must you be concertinaing? must she be concertinaing? must we be concertinaing? must you be concertinaing? must they be concertinaing?
Perfect	V-ing perfect
must I have concertinaed? must you have concertinaed? must she have concertinaed? must we have concertinaed? must you have concertinaed? must they have concertinaed?	must I have been concertinaing? must you have been concertinaing? must she have been concertinaing? must we have been concertinaing? must you have been concertinaing? must they have been concertinaing?

Interro-negative form

Simple form	V-ing form
mustn't I concertina? mustn't you concertina? mustn't she concertina? mustn't we concertina? mustn't you concertina? mustn't they concertina?	mustn't I be concertinaing? mustn't you be concertinaing? mustn't she be concertinaing? mustn't we be concertinaing? mustn't you be concertinaing? mustn't they be concertinaing?
Perfect	V-ing perfect
mustn't I have concertinaed? mustn't you have concertinaed? mustn't she have concertinaed? mustn't we have concertinaed? mustn't you have concertinaed? mustn't they have concertinaed?	mustn't I have been concertinaing? mustn't you have been concertinaing? mustn't she have been concertinaing? mustn't we have been concertinaing? mustn't you have been concertinaing? mustn't they have been concertinaing?